Shop by Manufacturer

Please Note

MarineEngine.com does not offer troubleshooting assistance or repair advice by email or by telephone. You are invited to join our public Boat Repair Forum to seek assistance from other members. You may also visit the Boat Motor Manuals section of our site to obtain a service manual.

1988 OMC 2.3L Semi-seized - Now what?

Hey guys...

Hoping you can help me out. Bought a 1988 Sunbird for $700. Hull, floor and Interior are in Excellent shape and motor looked clean with no visible cracks or leaks so took the risk even though it wasn't running. Lady said it ran 3 years ago but hadn't used it since. I'm sure she left it outside and never winterized it.

Put a new battery in it, motor turned about 1/4 inch than bound up.

So I pulled the outdrive and pulled the plugs and put some Murphy's mystery oil and tranny fluid in the cylinders and let it sit for about a week.

Today I pulled the front motor mount so I could get to the crankshaft. Put 3 bolts in the crankshaft pulley wheel and used a spanner wrench against the bolts to turn it by hand.

Good news is it moved (in both directions). Bad news is I can't turn it a full revolution. Gets about 95% of the way around in either direction and then binds HARD.

So doesn't seem like the pistons are seized but not sure what's causing the hard stop. Bent crankshaft? Valve? Something else?

I'm only an amateur mechanic. Good with tools and can fix most mechanical things but haven't rebuilt an engine since high school auto class 20 years ago.

So pulling the engine and rebuilding it probably a bit out of my league. May just have a new rebuilt engine put in it if necessary. Looks like they're about $2500.

I know it's an old boat and for $700 I'm willing to just scrap it as well. Just figured it was worth a shot since this is my 1st boat and want to make sure I'm gonna use it and work thru all the 1st time owner mistakes before I buy something nicer so willing to spend a few grand if necessary.